Windows and Hyper-V: the boot loader did not load an operating system

On Windows 11 Pro (last version), I’ve created a virtual disk with Disk2vhd (options vhdx and shadow copy) which is a copy of my C disk. I can mount it (D disk on the image) where EFI partition is visible.
Virtual disk

I’ve created a Virtual computer with Hyper-V using the previous disk (which was no more mounted), generation 2.

Virtual computer

I can start it, there is no error message.

Virtual computer started

When I connect to it, I get an error message.

Error message when connecting to virtual computer

Remark : I’ve no ISO of Windows System as it was alredy installed when I bought the PC
What do I miss? Thank you for any support